Refrigerating system



Dec. 15, 1931. yN. H. GAY 1,836,318

' REFRIGERATING SYSTEM Filed July 2'6, 192e 2 Sheets-sneet 1 um m INN, -Nw *QN WW. s@

`N WWU N N. H. GAY

REFRIGERATING SYSTEM Dec. 15, 1931.

' 2 Sheets-Sheet 2 Filed July 26, 1926 Patented Dec. l5, 1931 UNITED STATES PATENT oFEicE NORMAN H. GAY, OF LOS ANGELES, CALIFORNIA REFRIGERATING SYSTEM Y Appucaubn med my 26,

One object of this invention is to increase -the efiiciency of the evaporator of a refrigerating system by decreasing the back or outlet pressure thereon: and in particular by reducing this absolute pressure to below that at the low pressure side of the system. In conjunction therewith, liquid is separated from gas at the outlet of the evaporator and one or both are removed to the low pressure side of the system. In certain cases, the pressure difference between the inlet andv outlet portions of the evaporator is increased by raising the inlet pressure of liquid and lowering the outlet pressure of gas.

One object of this invention is to increase the efficiency of the evaporator and the compressor in a refrigerating system by removing obstructions to the passage of gas therebetween as formedby the passage of liquid along with the gas through the evaporator into the outlet manifold or header of the same; by thus decreasing the absolute pressure of the refrigerant gas in the evaporator and possibly icreasing the absolute pressure of the refrigerant gas passing to the compressor.

Another object is to accomplish this increase in efficiency by employing the energy contained within the refrigerating medium at a point where such energy is not at present utilized.

A further object' is to remove liquids from the outlet of the evaporator and to return them to the inlet of the same, and possibly to an oil trap connected therewith.

Further objects will appear in the course of the following specification and claims, and illustrative examples of embodiment of the invention are shown on the accompanying drawings.

1926. Serial No. 124,903.y

Fig. 1 is a diagrammatical layout of a refrigerating plant employing the presentinvention.

Fig. 2 is a diagram of a modified form of a portion of such a plant, likewise employing the invention.

Fig. 3 is a similar diagram of a further modified form.

In Fig. 1, an ordinary compressor-condenser-evaporator refrigerating system is represented in which the usual compressor 10 delivers the warm compressed refrigerant gas at a high pressure through the discharge line pipe 11 and the control Valve 12 into the condenser 13 in which the refrigerant gas is condensed in the usual manner into a liquid,

yand while still at the high pressure passes by gravity through a liquid line pipe and valve 14 into the receiver 15. The pressure prevailing upon the system forces this condensing refrigerant liquid through the king valve 16 and the liquid line pipe 17 into and through the pressure regulating valve 18, which is commonly called the expansion valve, and which may be referred to as an expander since it divides the high pressure portion of the system from the low pressure portion in conjunction with the compressor, and serves particularly to permit a partial evaporation of the liquid refrigerant sufficient to bring the remaining liquid refrigerant to the temperature prevailing in the low presL sure portion of the system.

All of these elements are common to and typical of the compression type of refrigerating plant and comprise the high pressure side of such a system, and form no part of this invention except as they constitute a part of a circuit in a plant to which the invention may be applied.

The refrigerant liquid upon leaving the pressure regulating valve 18 is atv a-lower pressure than in the liquid line 17 and at its entry into the pressure regulating valve 18 or so-called expander, and is at a temperature above the critical temperature of evaporation for the pressure at which it leaves the valve 18, and therefore a portion of it expands or evaporates so that the liquid is cooled to the temperature of evaporation at the relatively low pressure existing at the outlet from valve 18. This partial expansion or evaporation of the refrigerant liquid produces a stream of mingled refrigerant liquid and refrigerant gas at a pressure which is below the pressure existimr on the high pressure or condensing side ofa the system, but is still somewhat above the low pressure existing in the evaporator or low pressure side of the system. This mingled stream is caused to pass through the ejector nozzle into a separator chamber 20. Due to the velocity at which it passes from the ejector nozzle 19, al reduction of pressure is caused in the ejec tor housing 34 which is connected by the liquid line pipe 33 with the bottom ot' the outlet trap 30. The mingled stream of refrigerant liquid and refrigerant gas in combination with any additional liquid or gas from the liquid line pipe 33 and the trap 30 passes through the outer housing 32 and creates a further ejector action within this housing 32v and may or may not cause an increase of pressure in the separator chamber 20. A baffle 21 is disposed within the separator chamber 20 opposite the position of the ejector 19, and the mingled stream of liquid and gas from the ejector 19 and its housing 34 and 32 impinges against this baie 21, which is ap ropriately designed to separate the liquid rom the gas7 and cause the refrigerant liquid to pass into the lower portion of the separator 20 Where it collects in the pool 20x. The refrigerant gas which passes through the baliie 20 into the suction line pipe 35 returns to the compressor 10 to renew the cycle.

The separated liquid in the pool 20X is forced by the pressure existing in the separator 2O and also by the action of gravity, to pass downward through the refrigerant liquid line pipe 24 into the oil separator 26 The upper end of the liquid line pipe 24 is closable by the fioat valve 22 in the example shown in Fig. 1, so that a maintained level or head is provided for the pool 20", whereby the flow of gas refrigerant through the pipe 24 and the oil separator 26 into the evaporator is prevented7 and it is possible to maintain a pressure difference between the evaporator and the separator.

The refrigerant liquid passes from the oil separator 26 through a liquid line pipe and the valve 27 into the evaporator 28, which is of any suitable design as now well known in the art.A The greater portion of the refrigerant liquid entering the evaporator is evaporated therein and produces the desired refrigerating effect. and passes as refrigerant gas through the suction line pipe 29 into the trap 30. Under the conditions of practical operation, a varying proportion of unevaporated liquid refrigerant in the form of a fog or foam, or even in larger volumes of liquid which are commonly called slugs passes along with this gas into the suction line pipe 29. The greater portion of this unevaporated refrigerant liquid is separated from the refrigerant gas in the trap 30, and passes to the bottom of this trap to form a pool in the same; while the refrigerant gas free from such slugs passes out of the top of the trap 3() through the suction line pipe 31 and to the outer housing 32 of the 'ejector 19.

The liquid collecting in the bottom of the trap 30 is drawn off by the action of the ejector 19 through the liquid line pipe 33 into the ejector housing 34, and is thereby returned to the separator 20, and collects in the pool 20x in the bottom of the same. The refrigerant gas passing through the suction line pipe 31 ofthe ejector housing 32 enters the separator 2O and passes through the baffle 21 and pipe 35 on its return to thc compressor 10.

In this way, thc action of the ejector 19 is to decrease the absolute pressureprcvail ing Within the trap 30 both by the withdrawal of refrigerant gas through the suction line pipe 31, and by the withdrawal of liquid through the liquid line 33. Not only is the back pressure upon the evaporator 28 reduced, but also the liquid carried along into the outlet 29 of the evaporator is prevented from forming slugs or obstructions to the free passage of the refrigerant gas in its course away from the evaporator 28.

In the modified form of Fig. 2, the ejector 19 is connected with the pressure regulating valve 18 and the liquid line 17 as in Fig. l, and has an cjecting action into thc housing 34a as before, which is connected by the. liquid line 33a with the bottom of a trap 30a. which is connected as before by the suction line 29 with the evaporator 28. The housing 34a is connected to a separator chamber 2li/z. having a discharge liquid line 24a connected to its lower point and leading to the oil trap or separator 26a, which in turn is connected by a liquid line with a control valve 27 with the evaporator 28 in known manner. The bathe 21 in the separator 20a is for the same purpose and serves the same function as in Fig. 1. The upper part of the trap 30a is connected by a suction line pipe 31awith the scparator 20a.

In this modification, the ejecting action of the ejector nozzle 19 produces a suction in the housing 34a. which directs the liquid scpa'rated in the trap 30a through the liquid line 33a and returns it into the separator chamber 20a, where it is separated by means of the baille 21 and passes to the bottom of this chamber to form a liquid head on the pipe 24a and in the oil trap 26a. The refrigerant liquid and gas from the ejector 19 is separated lil tasas 1e as before and the liquid therefrom likewise passes through the pipe 24a to the evaporator. The low pressure at the outlet header of the evaporator in this instance is'maintained by the suction of refrigerant `liquid and gas through the liquid line 33a, in conjunction with the delivery f gas through the suction line 31a to the separator Chamber-20a. The other parts of the system may be the same as in Fig. l. This apparatus is in point for removing thc entrained refrigerant liquid from the refrigerant gas as it passes from the outlet header 29, and prevents the f ormation of slugs of liquid in the suction line pipe 31a.

ln the modified form of thc-invention according to Fig. 3, the ejector 19-B has an ejecting action into the housing iii-B placed in a vertical instead .of a horizontal position. The refrigerant liquid and gas coming from evaporator 28 through conduit 29 are separated in separator SO-B, the gas passing upward through conduit 31-B and the liquid falling into a pool in the bottom of separator BO--l From separator O-B the liquid flows by gravity througl'i conduit 33-B into housing 3LP-B. Here the. ejector action of the gas and liquid from the expansion valve l8-B. passing through line 19-B acts upon the liquid from conduit 33-13 both as an ejector and due to the entrained gas, the gas lifting action being similar to the air lifting action in an air lift well, the combined effect of the ejector and the gas lift action causing the liquid coming from conduit 33-B to pass upward and into separator QO-fB where the liquid is separated from the entrained gas by the separator arrangement 2l, the gas passing through conduit 35 to the compressor and the separated liquid falling to the hottom of chamber B and returning through conduit 24-B. oil separator 2GB-B, and conduit and valve 27 of the evaporator 28.

The other parts of the system may bc thc same as in Fig. l. l

This apparatus is in point for removing the entrained refrigerant liquid from the refrigerant gas as-it passes from the outlet header 29 and preventing thc formation of slugs of liquid in thc suction line pipe fil-B.

In each instance, the Compressor, condenser. expander and separator form a circuit; with a high pressure side from the compres; sor to the expander` and a low pressure side from the expander to the compressor.

It will bc understood that the invention is not restricted to the specific means shown for reducing the pressure existing at the outlet from the evaporator and for removing the entra-ined refrigerant liquid from the mingled gases at the outlet header of the evaporator. The invention provides means for effecting such a change of relative pressure, and for the removal of such liquid, and for the return of the liquid to the supply system for the refrigerator without causing the Hash gas, i. e., the gas generated in cooling the liquid from the temperature existing in the receiver to the temperature at which it enters the separator, to pass into the evaporator and thus produce a relatively high pressure .in such evaporator either due to the velocity and pressure at which it enters'the evaporator, or due to the great volume of gas which the evaporator must then handle.

The invention is not limited to the specific form of apparatus illustrated on the diagram or to the specific method of embodiment, but these may be modified Within the scope of the appended claims.

claim:

l. The combination in a refrigcrating system including a compressor, a condenser, a pressure regulating device, a separator and pipe lines connecting thc same in a circuit, an evaporator to receive liquid refrigerant from said separator, a liquid trap at the outlet of said evaporator, an ejector connected in the circuit between the pressure regulating device and the separator, and conduits from the top and bottom of said trap to said ejector, whereby said ejector may remove the gas and liquid from said trap separately.

2. The method of reducing the back pressureupon the evaporator of a rcfrigerating system which consists in separating the liquid and the gas at theoutlet of the evaporator, and employing the energy of the mixture of gaseous and l plid refrigerant coming from the high pressure portion of the system to remove the separated liquid and gas from the evaporator outlet.

3. The combination in a refrigerating system including a compressor, a condenser, an expander, a separator, and pipe lines connecting the same .in circuit, of an evaporator, a. conduit to deliver liquid refrigerant from said separator to said evaporator, an ejector connected in' the circuit between said expander and said separator and having two suction chambers, the outlet of said evaporator, and conduits respectively from the top and bottom of said trap to the chambers of said ejector whereby to remove the gas and liquid from the outlet of said evaporator and to reduce their back pressure thereat. y j

4. The combination in a refrigerafting system including a compressor, a condenser, an expander, a separator', and pipe lines to connect the same in a circuit, of an evaporator and a conduit to'deliver liquid refrigerant from said separator to said evaporator, means whereby said separator maintains va head of liquid upon said evaporator, a liquid trap communicating with the outlet of said evaporator, a conduit from the top of said trap to convey gas to said separator, a liquid removal conduit from the bottom of said a liquid trap connected to trap to remove the liquid from said trap, and an ejector connected in the circuit between said expander and said separater and adapted to move the separated liquid through said removal conduit.

5. The method of operating a refrigerating system which comprises producingr refrigerating liquid under high pressure, delivering the refrigerant liquid under a lower inlet pressure to an evaporator so that a part thereof is gasified, separating the gasied portion prior to entering the evaporator and returning it for the production of refrigerating liquid under high pressure, withdrawing the refrigerant from said evaporator at a lesser pressure than at the evaporator inlet, separating the efflux from said evaporator into gaseous and liquid components, and employingr the energy of said refrigerating liquid in passing from said high pressure to said inlet pressure to restore said separated liquid component to said inlet pressure and to return it to the inlet of said evaporator.

6. Method of operating a refrigerating system comprising a compressor-condenserexpander-separator circuit with an evaporator having its inlet connected to said separator, which consists in maintaining a head of liquid refrigerant on said evaporator, cmploying the energy of the refrigerant from the expander to withdraw mixed gaseous and liquid refrigerant from said evaporator at a greater rate than the evaporation therein, separating the withdrawn gas and liquid and returning the gas and liquid separately to said separator.

7. The combination in a refrigerating system including a compressor, a condenser, an expander, a separator and pipe lines to connect the saine in a circuit, of an evaporator, a conduit to deliver liquid refrigerant from said separator to said evaporator,

vmeans whereby said separatormaintains a head of liquid upon said evaporator, said means including a float valve in said conduit and controlled by the level of liquid in said separator to prevent the passage of gas through said conduit, an eJcctor connected in said circuit between the expander and the separator, a liquid trap connected to the outlet of said evaporator to collect liquid refrigerant while the gaseous refrigerant is permitted to How to the separator, and a conduit from the trap to said ejector to accelerate the removal of the gaseous refrigerant from said trap whereby to reduce the back pressure of gaseous refrigerant at said evaporator with respect to the pressure in said separator.

S. 'lhe combination in a refrigerating system including a compressor, a condenser, an expander, a separatorv` and pipe lines to connect the same in a circuit, of an evaporator and a conduit to deliver liquid refrigerant from said separator to said evaporator, said separator being located above said evaporater, a liquid trap communicating with the outlet of said evaporator, a conduit from the top of said trap to convey gas to said separator, and a liquid rcnroval conduit from the bottom of said trap to remove the liquid from said trap and deliver such liquid into the said pipe line between'said expander and said separator and opening into the same at a point below the liquid refrigerant level in said liquid trap so that the buoyant effect of the mixing of the gas and liquid from the expander with the liquid from the liquid trap will lift such liquid in the said pipe line toward said separator.

9. The combination in a refrigerating system including a compressor, a condenser, an expander, a separator, and pipe lines to connect the saine in a circuit, of an evaporator and a conduit to deliver liquid refrigerant from said separator to said evaporator, said separator being located above said evaporator, a liquid trap communicating with the outlet of said evaporator, a conduit from the top of said trap to convey gas to said separator, a liquid removal conduit from the bottoni of said trap to remove the liquid from said trap, and an ejector connected in the said pipe line between said expander and said separator and located below the liquid level in said liquid trap so that the energy of said liquid and gaseous refrigerant entering said ejector from said expander' operates to lift the liquid from said liquid trap, and the lmoyautelfect of the mixture of gaseous and liquid refrigerant from said expander upon the liquid from said liquid trap assists in such lifting.

10. The combination in a refrigerating system having high and low pressure portions, of an evaporator, a separator for gaseous and liquid refrigerant, a liquid trap connected to the outlet of said evaporator, a conduit from said separator to pass liquid refrigerant to said evaporator; said evaporator, separator, trap and conduit being included in said low pressure portion of the system; means operated by the energy liberated in the passage of refrigerant from the high pressure portion to the low pressure portion of the system to reduce the pressure in said trap below that in said separator and to prevent the passage of gas from said separator to said trap, and means to prevent the passage of gas from said separator into said evaporator.

11. The combination in a refrigerating system having high and low pressure portions, of an evaporator, a separator' for gaseous and liquid refrigerant, a liquid trap connected to the outlet of said evaporator. a conduit from said separator to pass liquid refrigerant tov said evaporator: said evaporator, srqiarator, trap and conduit being included in said low pressure portion of the system, and means to return the liquid and gaseous refrigerant from said trap to the separator independently of one another, means operated by the energy liberated in the passage of refrigerant from the high pressure portion to the W pressureporton to reduce the pressure in said trap below that n said separator and to pre- 5 vent thepassage of gas from said separator to said trap, means connected to said separator to return the gaseous refrigerant for recompression and reliquefaetion, and means to prevent the-passage of gas from said sepaw rator into said evaporator.

In testimony whereof, I aiX my signature.

, VNORlVIANI-I. GAY. 

